Spain's Alex Palou has taken the lead in the Indycar Championship after winning the Indianapolis Grand Prix by 16.8 seconds over Mexican Pato O'Ward.

The 2021 series champion inherited the lead on lap 65 of the 85-lap race, then drove away from the pack to claim victory for his Chip Ganassi Racing team.

It was Palou's fifth win since joining the series in 2020 and he leads to 2023 series on 174 points, six clear of O'Ward who has been the runner-up three times in five races this season.

"We honestly knew we had a fast car yesterday," the Spaniard said. "The car has been fast all weekend. I just had to execute."

Alexander Rossi, the 2016 Indianapolis 500 winner, finished third. Pole winner Christian Lundgaard finished fourth for Rahal Letterman Lanigan Racing - his second straight top-five finish on Indy's 14-turn, 2.439-mile road course.

Australia's defending Indycar series champion Will Power had to settle for 12th place, while former Australian Supercars champion Scott McLaughlin was 16th.

McLaughlin dropped to fifth in the season standings on 133 points while Power is eighth with 122 points.

The race came down to tire strategy late.

Lundgaard and Palou pitted on opposite ends of lap 60 with Lundgaard going with sticker primaries while Palou went with scuffed tires. O'Ward pitted three laps later and took the softer sticker reds.

And when Rossi pitted on lap 65, going with reds, Palou moved to the front of the pack and kept pulling away.

Marcus Ericsson, the defending Indianapolis 500 champion, finished eighth and dropped two spots in the points chase to third, 18 points behind his teammate Palou.

Practice for the Indianapolis 500 begins on Tuesday on the track's historic 2.5-mile oval.

Pole qualifying will be held next Saturday with Bump Day set for May 21. IndyCar's biggest race of the season will be run May 28.